ASEXUAL AND SEXUAL REPRODUCTION

• SEXUAL REPRODUCTION

  A type of reproduction in which the genetic materials from two different cells combine, producing an offspring
• The cells that combine are called sex cells
• FERTILIZATION

  an egg cell and a sperm cell join together
• A new cell is formed and is called a zygote
• ADVANTAGES OF SEXUAL REPRODUCTION:

  • Diverse offspring
  • Selective breeding
• DIVERSE OFFSPRING

  genetic variation among offspring where Half of the DNA comes from mom and Half of the DNA comes from dad
• TRAITS

  can develop to resist harsh environments that allows an organism survive
• SELECTIVE BREEDING

  used to develop many types of plants and animals that have desirable traits
• ASEXUAL REPRODUCTION

  • One parent: organism produces offspring without fertilization
  • Uniform offspring: 
  • Because offspring inherit all of their DNA from one parent, they are genetically identical to each other and to their parent
• 4 types of asexual reproduction

  1. FISSION
  2. BUDDING
  3. REGENERATION
  4. VEGETATIVE PROPAGATION
• FISSION:

  • Cell division in prokaryotes that forms two genetically identical cells 
  • DNA is copied
  • The cell begins to grow longer, pulling the two copies apart
  • The cell membrane pinches inward in the middle of the cell
  • Cell splits to form two new uniform, identical offspring
  • Examples: bacteria, Ecoli, pond critters
• BUDDING:

  • A new organism grows by mitosis and cell division on the body of its parent
  • The bud, or offspring is identical to the parent
  • The bud, when large enough, can break off of the parent and live on its own
  • Offspring may remain attached and form a colony
  • Examples: Yeast, Hydra, cactus
• REGENERATION:

  • Occurs when an offspring grows from a piece of its parent.  
  • Producing new organisms: Sea Stars
  • Sea urchins, sea cucumber, sponges, and planarians
  • Producing new body parts: Gecko
  • Newts, tadpoles, crabs, hydra, and zebra fish
• VEGETATIVE PROPAGATION:

  • Uniform offspring grow from a part of a parent plant
  • Parent plants sends out runners
  • Where the runner touches the ground, roots can grow
  • A new plant is produced even if the runner is broken apart
  • Each new plant is uniform and identical to the parent. 
  • Examples: strawberries, potatoes, ivy, crabgrass